Grand Caravan V6-3.8L VIN L (2007)
Control Module HVAC: Description and Operation
Front Blower Motor Power Module - Operation
OPERATION
The front blower motor power module is connected to the vehicle electrical system through a dedicated lead and connector of the front HVAC wire
harness. A second connector receptacle receives the wire harness connector from the front blower motor. The front blower motor power module allows
the microprocessor-based automatic temperature control (ATC) A/C-heater control to calculate and provide infinitely variable blower motor speeds
based upon either manual blower switch input or the ATC programming using a pulse width modulated (PWM) circuit strategy.
The PWM voltage is applied to a comparator circuit which compares the PWM signal voltage to the front blower motor feedback voltage. The resulting
output drives the power module circuitry, which provides a linear output voltage to change or maintain the desired blower speed.
The front blower motor power module is diagnosed using a DRBIII(R) scan tool.
The front blower motor power module cannot be adjusted or repaired and must be replaced if found inoperative or damaged.
